Wisconsin taxpayers have been forced to spend millions of dollars to take care of empty Milwaukee Public Schools buildings the district refuses to sell to choice school operators.

MPS' 15 vacant structures, some of which have been unused for close to a decade, are costing state and local taxpayers approximately $711,000 per year in utility and maintenance expenses.

Wisconsin Reporter did a study of the 10 largest school districts in the state and found that, compared to Milwaukee, the nine others have a combined total of just five idle buildings, costing taxpayers about $83,000 a year.

MPS spokesman Anthony Tagliavia partly attributes that difference to the Milwaukee district having the biggest facility inventory and the greatest number of students.

But dwindling enrollment also is undoubtedly playing a role.

MPS, which consists of numerous low-performing schools, has seen its student population drop from 92,395 in 2005-06 to an estimated 78,599 in 2013-14, according to data from the Wisconsin Department of Public Instruction.

MPS has been blocking several charter and private schools in the choice program from buying nearly every one of its unused facilities, an investigation conducted by the Wisconsin Institute for Law and Liberty has revealed.